THE DAILY DOWNLOAD / ANTHROPIC / CLAUDE
Claude levelled up twice in one week. Faster, and cheaper to run.
Anthropic shipped Claude Opus 5.5 on Sept 22 and Sonnet 5.5 on Sept 28. Both are 30%+ faster, and one of them finally beat Pokémon Red.
The TL;DR
- Opus 5.5 performs at the level of Anthropic's top model on most work, writes 30%+ faster than Opus 5 and costs about 40% less to run.
- Sonnet 5.5, the everyday all-rounder, is the fastest Sonnet yet at the same developer price.
- Flex of the week: Sonnet 5.5 is the first Sonnet to beat Pokémon Red working only from screenshots.
If AI model names make your eyes glaze over, here's the cheat code. Opus is Claude's big brain. Sonnet is the everyday all-rounder. The number going up means it got better. This week both hit 5.5, six days apart.
Opus 5.5 (Sept 22) is the headline. Anthropic says it performs at the level of Claude Fable 5.1, its most capable model, on most work, while writing answers more than 30% faster and costing about 40% less to run than Opus 5. One early tester used it to finish a 680,000-line code migration in less than a day. That's the kind of job that used to eat a team's whole quarter.
Sonnet 5.5 (Sept 28) arrived at the same developer price as before, runs 30%+ faster than Sonnet 5 and jumped from 10.3% to 70.6% on Terminal-Bench 4.0, a test of doing real tasks on a computer. And yes, it became the first Sonnet to finish Pokémon Red using nothing but screenshots. Gen Alpha: it's giving speedrun. Millennials: we were not that patient with Brock either.
Anthropic also says Opus 5.5 is the strongest model it has tested on its alignment audits, the checks that a model behaves the way it's supposed to.
Why you should care
Faster, cheaper models mean snappier answers in the Claude app and smarter features in the apps built on Claude, without a price hike. If you use AI to write, study or work, this is the best kind of upgrade: the one you don't have to do anything for.
Vibe check
No cap, a glow-up with no price hike.